Screen Data Fields

InfoWorks ICM allows the modelling of sloping bar screens in the network. A screen is used to trap debris in the network, possibly at the entrance to a treatment works.

The calculation method uses the Kirschmer formula, which is appropriate for clean screens. For screens that are partially blocked it may be more appropriate to use a User-Defined Control and define a Head Discharge Table to represent the screen.

Screen data can be edited on either the Screen Grid Window of the Links Grid or the Screen Property Sheet.

To view and edit all screen data, use the Property Sheet.

This table describes all the screen specific data which can be used to define a screen. For details of results fields, see the Link Results Data Fields topic.

Common Data Fields

Fields that are common to the majority of objects can be found in the Common Fields topic.

Screen Data

Database Table Name: hw_screen

Show Columns

Database Names

Size, Type and Units

Defaults and Error Limits

Field Name

Help Text

Database Field

Data Type

Size

Units

Precision

Default

Error Lower Limit

Error Upper Limit

Warning Lower Limit

 Warning Upper Limit

Crest

Crest Level is the level above datum of the base of the screen.

crest

Double

 

Z

3

 

-9999

9999

 

6000

Width

The total width of the screen, including bars and bar spaces.

width

Double

 

L

3

 

0

 

 

 

Height

The total height of the screen.

height

Double

 

L

3

 

0

 

 

 

Angle

Screen sectionThe angle of the screen measured in degrees from the vertical axis. Therefore a vertical screen has an angle of zero degrees.

InfoWorks ICM assumes that screens are either vertical or leaning forward in the direction of flow. There is no support for negative angles.

angle

Double

 

ANGLE

2

0

0

89

 

 

Kirschmer's shape factor

InfoWorks ICM uses the Kirschmer formula to calculate the head difference through the screen. See Screens.

Typical values for the Kirschmer coefficient are:

Sharp edged rectangular bars

2.42

Semi-circular upstream face

1.83

Semi-circular upstream and downstream faces

1.67

Circular bars

1.79

kirschmer

Double

 

 

2

1.79

0.01

 

 

 

Bar width

The thickness of the bars making up the screen.

bar_width

Double

 

PS

1

 

0.000001

 

 

 

Bar spacing

The width of the clear gap between the bars. This is NOT the distance between the centre of the bars.

bar_spacing

Double

 

PS

1

 

0.000001

 

 

 

US node ID

Type in a node reference or choose an existing node reference from the dropdown list. This makes up the first part of the link reference.

us_node_id

Text

64

 

0

 

 

 

 

 

Link suffix

A single character between A and Z or 0 and 9 which completes the link reference. This allows a node to have up to 36 downstream links. The suffix is automatically allocated by the software.

link_suffix

Text

1

 

0

1

 

 

 

 

DS node ID

Type in a node reference, or choose an existing node reference from the dropdown list.

ds_node_id

Text

64

 

0

 

 

 

 

 

Link type

There are no additional options. The field is hidden on the grid, and read-only on the property sheet.

link_type

Text

6

 

0

SCREEN

 

 

 

 

System type

Choose the system type from the dropdown list. See System Type for more information.

Database Value

Description

 Help Text

STORM

 Storm Rainfall collection system

FOUL

 Foul Wastewater collection system (UK terminology)
SANITARY Sanitary Wastewater collection system (US terminology)
COMBINED Combined Rainfall and wastewater collection system
OVERLAND Overland Overland floodwater collection system
OTHER Other Other system type

system_type

Text

10

 

0

Other

 

 

 

 

Asset ID

For reference only. Designed as a reference to an asset database, but could be used for anything.

asset_id

Text

64

 

0

 

 

 

 

 

Sewer Reference

An optional reference to identify the sewer of which this conduit is a part.

sewer_reference

Text

80

 

0

 

 

 

 

 

Points

This field defines the geometry of the link. The underlying data consists of a series of (x,y) pairs defining the vertices of the link. Each link is made up of a series of straight lines between the defined (x,y) points.

This data is not displayed on the grid or property sheet.

Link Vertice Export

Link vertices are included when you export link data to CSV files. There are two options available for exporting link vertices. These are selected on the Select CSV Export Options Dialog using the Coordinate Arrays Format dropdown list. The options are:

  • Packed - The data is exported as a series of x,y pairs.

  • Separately - the data is appended to the end of the row containing the link data. Each x and y value is in a separate (comma separated) field.

point_array

Array

 

XY

0

 

 

 

 

 

DS settlement efficiency (%)

Closed

Water Quality

This section is relevant only to Water Quality Simulations. If the icon is at the start of a paragraph, then that paragraph is only relevant to water quality simulations. If the icon is at the top of a topic, or a section (underneath a section title), or a row in a table, then the complete topic, section or row is only relevant to water quality simulations.

See US settlement efficiency.

ds_settlement_eff

Long Integer

 

 

0

0

0

100

 

 

US settlement efficiency (%)

Closed

Water Quality

This section is relevant only to Water Quality Simulations. If the icon is at the start of a paragraph, then that paragraph is only relevant to water quality simulations. If the icon is at the top of a topic, or a section (underneath a section title), or a row in a table, then the complete topic, section or row is only relevant to water quality simulations.

The settlement efficiency fields allow you to set the effectiveness of an overflow for trapping out sediment. The overflow is a link (normally a pipe) attached to a node acting as a storage tank (storage node or manhole).

Normally the upstream end of the link will be attached to the node and act as the overflow.

The upstream settlement efficiency determines the efficiency for the overflow.

In some circumstances the link may be reversed (storage tank at the downstream end) and the downstream settlement efficiency will be used.

In many cases an overflow will attach to an outfall from the system.

It would be very unusual to have both upstream settlement efficiency and downstream settlement efficiency set to non-zero values.

The valid range is 0-100%. 0% means the overflow acts as a normal continuation link. 100% means that the overflow traps out as much sediment as possible.

us_settlement_eff

Long Integer

 

 

0

0

0

100

 

 

Branch ID

Numeric field used to identify to which long section the link is associated.

Can be set manually or automatically (see Defining Branches topic for more information).

branch_id

Long Integer

 

 

0

 

0

 

 

 

InfoAsset unique ID

Unique ID associated with the corresponding object in an InfoAsset Manager database. When importing from InfoAsset Manager, the InfoAsset ID can be copied from the InfoAsset database in order to maintain links between the two networks.

asset_uid

GUID

 

 

0

 

0

0

0

0
InfoAsset ID

Used to store the ID of the corresponding InfoAsset object when Importing from a Collection Network.

 infonet_id Text 40   0          

Screens

Links Grid

Property Sheets